The ability to display fluorescence when exposed to UV light is an extraordinary feature shared among several phyla in the biological world. Even among vertebrates, biofluorescence has been observed in several classes, inhabiting the most diverse environments from the deep ocean to tropical rainforests. Reptiles and Amphibians are no exceptions: bone and dermal  fluorescence have been observed in various geckos, chameleon and snake species. In Amphibian, bone, dermal and ocular biofluorescence have been described in frogs, toads and treefrogs inhabiting tropical and subtropical regions. 

To contribute to a better understanding of the diffusion and biological role of biofluorescence, a study that will soon be published on Acta Herpetologica explored this feature in several Amphibian and Reptile species from the Atlantic Forest in Brazil. The study, that encompassed 29 species, found biofluorescence in 5 Amphibian species (namely Brachycephalus nodoterga, Scinax argyreornatus, Bokermannohyla alvarengai, Hylodes phyllodes and H. asper) and 4 Reptile species (Enyalius perditus, Hemidactylus mabouia, Bothrops jararaca and B. jararacussu). 

In the amphibian species included in the study, UV fluorescence may play a role in intraspecific communication and mate choice, complementing advertisement calls and making individuals conspicuous even in low-light environments. Alternatively, it may serve as a means for communicating with sympatric species to avoid conflict over resource use.

More intriguing is the finding that in pit vipers (Bothrops jararaca and B. jararacussu), the tail tip shows marked fluorescence only in juveniles. Young pit vipers primarily prey on frogs, and it is proposed that the biofluorescent tail tip might serve as a lure to attract amphibians at night. Coherently, the feature is lost in adult pit vipers, which mainly eat small mammals by ambush or active hunt.

Further insights in the fascinating  use of UV light in Amphibian and Reptiles are expected from future studies, which should investigate species from other localities and make use of different UV wavelengths than those used in the present study. 

Preview the study here!

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